Traditional coaxial twin-propeller aerial vehicles can be classified into two types: single-motor driven and twin-motor driven. The motor of the single-motor aerial vehicle must drive two propellers. In the driving process, a transmission component such as gear or belt is often used to change the drive direction of motor so that the propellers rotate in opposite directions at the same rotational speed. A disadvantage of the single-motor aerial vehicle is that its carrying capacity is low, so it is not suitable to carry an extra camera module, and usually a lightweight camera module is in-built inside the aerial vehicle. Since the camera module is directly attached to the aerial vehicle, it is not convenient to replace the camera module.
On the other hand, the carrying capacity of the twin-motor aerial vehicle is higher than that of the single-motor aerial vehicle. The motor layout of the twin-motor aerial vehicle includes two types: a vertical layout and a horizontal layout. The twin-motor aerial vehicle with a horizontal layout must use a transmission component such as gear and belt to drive the upper and lower propellers. A disadvantage of the twin-motor aerial vehicle with a horizontal layout is that it must use a transmission component such as gear and belt to drive the propellers and the transmission components have the problem of being worn and aging.
On the other hand, the twin-motor aerial vehicle with a vertical layout needs a wiring rack installed outside the propeller, and the wires run between the motor and the propeller with the aid of the wiring rack. A disadvantage of the twin-motor aerial vehicle with a vertical layout is that the wiring is difficult and it needs additional installation of a wiring rack, which results in the increase of the weight of aerial vehicle.